PT-2000 Documentation Print
Medium-pressure transducers are used in a multitude of research and teaching applications, ranging from keeping track of barometric pressure to measuring or controlling hypobaric environments and testing nominally gas-tight equipment for leaks. To take only barometric pressure as an example, it has now been established that many whole-animal studies are profoundly influenced by ambient pressure levels. Recording this often-neglected variable during experiments may yield clues to otherwise puzzling phenomena. And, of course, any gas analysis setup that does not employ mass flow control or mass flow metering absolutely requires knowledge of, and preferably continuous recording of, barometric pressure.

Previously, the only practical absolute pressure-measurement device was a standard aneroid barometer. These devices can be quite accurate, if you're willing to pay several hundred dollars for one. Unfortunately they are delicate and can even be ruined by exposure to the unpressurized hold of an aircraft. And of course they are useless for long-term recording unless you purchase a recording aneroid barometer, which is still more expensive and far more temperemental than a conventional barometer. And a recording barometer can't be connected to a data acquisition system in any straightforward way.

Technology marches on. What used to require delicate wire levers and precise gears coupled to a metal accordion can now be done better with a precision-etched silicon wafer, thin enough to flex slightly under pressure and containing integral temperature-compensated silicon strain gauges. These wafers are ideal pressure transducers, offering high sensitivity, very low drift and superb resolution and frequency response.

The Sable Systems PT-2000 pressure meter, based on a precision silicon wafer pressure sensing element, is designed for stand-alone use or for direct connection to any data acquisition system or chart recorder. It has a basic range of 0 -120 kPa, in absolute mode. In this mode it has a panel-meter resolution of 0.1 kPa and a voltage output of 25 kPa/V. The available resolution is better than 0.01 kPa if the PT-2000 is connected to a suitable 16-bit data acquisition system such as ExpeData. The PT-2000 is calibrated against a gold standard, NIST-traceable pressure meter, so you can be sure of its accuracy.

Many applications call for measuring small changes in pressure anywhere over the instrument's range. The PT-2000 excels at this, with full offsetting and gain capability over the entire range of the instrument. This capability allows you to subtract a constant offset from the pressure transducer's output, and amplify only deviations from that value.

The PT-2000 even has an invaluable feature you won't find on any other commercially-available instrument. As an alternative to manually setting the offset value it can offset itself automatically, canceling long-term pressure drifts but faithfully amplifying the more rapid signals of interest. It can do this with either of two time-constants (10 or 60 seconds). This makes the PT-2000 a "natural" for demanding applications in which a tiny, rapidly-varying signal rides on a much larger, more slowly-varying signal.

In addition to its other uses, the PT-2000 can be used as the primary transducer in a pressure-regulation system for controlling pressures anywhere from tens of Pa to full sea-level barometric pressure. How? Just connect the PT-2000 to a suitable control system. Curious about the effects of hypobaric hypoxia or any other low-pressure phenomena? If you've already got a PT-2000 and ExpeData or another good data acquisition system, you can control, ramp and vary pressures with just a pump and a few dollars' worth of extra components - at a tiny fraction of the cost of a dedicated commercial pressure-regulation system!

The PT-2000 is very affordable and like all Sable Systems instrumentation the PT-2000 is constructed to last, thanks to top-quality components. As a mark of our confidence it comes with a three-year guarantee.

The PT-2000 requires only an uncritical 10 - 20VDC power source (a 120VAC to 12VDC unit is included; other input voltages are available to special order) and a good home in your laboratory.

If you have any questions about our PT-2000 or any of our other products, do not hesitate to contact us.

 

 
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